Disodium ar,ar'-[(9,10-dihydro-9,10-dioxo-1,4-anthrylene)diimino]bis[(4-chlorophenoxy)benzenesulphonate]

Endpoint summary

Description of key information

Not skin sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

From February 28 to April 28, 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Justification for type of information:

The read across approach is detailed into the document attached below.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adapted July 17, 1992

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

July 31, 1992

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Old study

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Ciba-Geigy Ltd. breeder.
- Weight at study initiation: between 326 to 400 g.
- Housing: the animals were housed individually in Macrolon cages (Type 3).
- Diet: standard guinea pig pellets - NAFAG No. 845, Gossau SG, ad libitum. All batches of the diet are assayed for nutritive ingredients and contamination level by the manufacturer.
- Water: fresh water, ad libitum. The drinking water quality fulfilled the critical parameters in the specifications of the "Schweizerisches Lebensmittelbuch"
(Edition 1972). The results of the routine chemical examination of water at source as conducted periodically by the water authority are available to the testing facility.
- Sensitivity of strain: the sensitivity of the strain is checked once or twice a year with a known mild to moderate sensitiser, such as mercaptobenzothiazole, hexyl cinnamic aldehyde or potassiumdichromate.

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Relative humidity: 30 to 70 %
- Photoperiod: 12 hours light cycle day.

No. of animals per dose:

20 test and 10 control animals.

Details on study design:

RANGE FINDING TESTS
Intradermal Induction
- Test concentration: 5 % in physiological saline (w/v).
- Results of intradermal injection: 5 % test item in physiological saline could be injected and was well tolerated.

Epidermal Applications (induction and challenge)
- Readon for concentrations choice: the concentrations for the epidermal applications were selected on account of the primary irritation potential of the test article.
- Test concentrations: 10, 20, 30, and 50 % in physiological saline; 50 % was the highest possible concentration of the test article in physiological saline.
- Results of epidermal applications: reactions were observed with 20, 30, and 50 % in physiological saline.

MAIN STUDY
A. INDUCTION EXPOSURE
Intradermal injections - day 0
- No. of exposures: 3 pairs of intradermal injections (0.1 ml per injection).
- Test groups: adjuvant/saline mixture 1:1 (v/v); 5 % test item in physiological saline (w/v); 5 % FAT 21030/D in the adjuvant/saline mixture (w/v)
- Control group: adjuvant/saline mixture 1:1 (v/v); adjuvant/saline mixture 1:1 (v/v); physiological saline
- Site: intradermal injections were made simultaneously into the left and right side of the shaved neck of the test and control group animals.
- Observations: after the intradermal induction application irritant reactions are normally induced by the adjuvant and the high test article concentration. Because most of the reactions are treatment related and not compound related, the reactions are only described in special cases in the section of results.

Epidermal application - day 8
DAY 8: INDUCTION, epidermal application
- No. of exposures: one exposure.
- Test group: 50 % test item in physiological saline.
- Control group: physiological saline only.
- Application: occluded administration; the test item was incorporated in physiological saline and applied on a filterpaper patch to the neck of the animals.
- Application site: patch 2x4 cm; approx. 0.4 g per patch.
- Duration of exposure: 48 hours.
- Observations: after the epidermal induction application irritant reactions are normally induced by the adjuvant and the high test article concentration. Because most of the reactions are treatment related and not compound related, the reactions are only described in special cases in the section of results.

B. CHALLENGE EXPOSURE - day 21
- No. of exposures:
- Test group: 10 % test item in physiological saline.
- Control group: physiological saline only.
- Application: occluded administration; animals were tested on one flank.
- Application site: patch 2x2 cm; approx. 0.2 g per patch.
- Duration of exposure: 24 hours.
- Observations: 24 and 48 hours after removing the dressings, the challenge reactions were graded according to the Draize scoring scale.

ADDITIONAL OBSERVATION AND RECORS
The body weight was recorded at start and end of the test.

INTERPRETATION OF RESULTS
The sensitising potential of test item was classified according to the grading of Magnusson and Kligman.

According to the guide to the labelling of dangerous substances and the criteria for the choice of sentences indicating particular hazards (R sentences) attributed to dangerous substances (Commission Directive 93/21/EEC, April 27, 1993) a test article was classified as a sensitiser in the case where a positive response was noted in at least 30 % of the animals.

Positive control substance(s):

yes

Remarks:

2-Mercaptobenzothiazole

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

challenge at 10 % in physiological saline

No. with + reactions:

1

Total no. in group:

20

Remarks on result:

no indication of skin sensitisation

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

no indication of skin sensitisation

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

challenge at 30 % in vaseline

No. with + reactions:

20

Total no. in group:

20

Remarks on result:

positive indication of skin sensitisation

Body weights were not affected by treatment.

Under the experimental conditions employed, 5 % of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

Test item is, therefore, classified as a weak sensitiser in albino guinea pigs according to the grading of Magnusson and Kligman.

Number of positive animals per group after occlusive epidermal application

Control group
	After 24 hrs	After 48 hrs
Vehicle control	0/10	0/10
Test article	0/10	0/10
Test group
Vehicle control	0/20	0/20
Test article	1/20	1/20

Challenge reactions after epidermal application

Animal N / sex	24 hrs		48 hrs
	Erythema	Oedema	Erythema	Oedema
Vehicle control
M 266	0	0	0	0
M 267	0	0	0	0
M 268	0	0	0	0
M 269	0	0	0	0
M 270	0	0	0	0
M106	0	0	0	0
M107	0	0	0	0
M108	0	0	0	0
M109	0	0	0	0
M110	0	0	0	0
M 276	0	0	0	0
M 277	0	0	0	0
M 278	0	0	0	0
M 279	0	0	0	0
M 280	0	0	0	0
F116	0	0	0	0
F117	0	0	0	0
F118	0	0	0	0
F119	0	0	0	0
F120	0	0	0	0
Test article
M 266	0	0	0	0
M 267	0	0	0	0
M 268	1	1	1	0
M 269	0	0	0	0
M 270	0	0	0	0
M106	0	0	0	0
M107	0	0	0	0
M108	0	0	0	0
M109	0	0	0	0
M110	0	0	0	0
M 276	0	0	0	0
M 277	0	0	0	0
M 278	0	0	0	0
M 279	0	0	0	0
M 280	0	0	0	0
F116	0	0	0	0
F117	0	0	0	0
F118	0	0	0	0
F119	0	0	0	0
F120	0	0	0	0

DRAIZE Score after removal of the dressing

Animal N / sex	24 hrs		48 hrs
	Erythema	Oedema	Erythema	Oedema
Vehicle control
M 261	0	0	0	0
M 262	0	0	0	0
M 263	0	0	0	0
M 264	0	0	0	0
M 265	0	0	0	0
F111	0	0	0	0
F112	0	0	0	0
F113	0	0	0	0
F114	0	0	0	0
F115	0	0	0	0
Test article control
M 261	0	0	0	0
M 262	0	0	0	0
M 263	0	0	0	0
M 264	0	0	0	0
M 265	0	0	0	0
F111	0	0	0	0
F112	0	0	0	0
F113	0	0	0	0
F114	0	0	0	0
F115	0	0	0	0

Interpretation of results:

other: not classified, according to the CLP Regulation (EC) No 1272/2008

Conclusions:

Not sensitising

Executive summary:

A study was performed to assess the contact sensitisation potential of the test material in the albino guinea pig. The study, a Guinea Pig Maximization Test, was performed in compliance with the requirements of OECD guideline 406.

The test was started with the minimum number of animals (5 per sex for the test group and 5 of one sex for controls). After the challenge procedure, it was not possible to conclude if the test substance is a ssensitizer or not and therefore testing in additional animals was performed to give a total of 20 test and 10 control animals.

The concentration for the intradermal injections was selected on account of the solubility of the test article in standard vehicles and its local and systemic tolerability in a pretest. Based on the results of a preliminary test, the concentration of the test compound for the induction and challenge phases were selected as follows: 5 % of test item in physiological saline for intradermal induction; 50 % of test item in physiological saline for epidermal induction; 10 % or test item in physiological saline for challenge.

The challenge reactions were recorded 24 and 48 hours after removing the dressings, according to the Draize scoring scale. The sensitising potential of test item was classified according to the grading of Magnusson and Kligman.

Under the experimental conditions employed, 5 % of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

Test item is, therefore, classified as a weak sensitiser in albino guinea pigs according to the grading of Magnusson and Kligman.

Body weights were not affected by treatment.

Conclusion

Since positive response was observed in less than 30 % of the treated animals, responding at anintradermal induction dose greater than 1 %, the substance does not meet the criteria to be classified as skin sensitizer, according to the CLP Regulation (EC) 1272/2008.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A study was performed to assess the contact sensitisation potential of the test material in the albino guinea pig. The study, a Guinea Pig Maximization Test, was performed in compliance with the requirements of OECD guideline 406.

The test was started with the minimum number of animals (5 per sex for the test group and 5 of one sex for controls). After the challenge procedure, it was not possible to conclude if the test substance is a sensitizer or not and therefore testing in additional animals was performed to give a total of 20 test and 10 control animals.

The concentration for the intradermal injections was selected on account of the solubility of the test article in standard vehicles and its local and systemic tolerability in a pretest. Based on the results of a preliminary test, the concentration of the test compound for the induction and challenge phases were selected as follows: 5 % of test item in physiological saline for intradermal induction; 50 % of test item in physiological saline for epidermal induction; 10 % or test item in physiological saline for challenge.

The challenge reactions were recorded 24 and 48 hours after removing the dressings, according to the Draize scoring scale. The sensitising potential of test item was classified according to the grading of Magnusson and Kligman.

Under the experimental conditions employed, 5 % of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings. Body weights were not affected by treatment.

Since positive response was observed in less than 30 % of the treated animals, responding at an intradermal induction dose greater than 1 %, the substance does not meet the criteria to be classified as skin sensitizer, according to the CLP Regulation (EC) 1272/2008.

Justification for classification or non-classification

According to the CLP Regulation (EC) No 1272/2008, 3.4.2.2 skin sensitisation section, skin sensitizer means a substance that will lead to an allergic response following skin contact. Effects seen in either humans or animals will normally justify classification in a weight of evidence approach for skin sensitizers.

In the GPMT performed, less than 30 % of animals showed reactions responding to an intradermal induction dose higher than 1 %.

Therefore, the substance does not meets the criteria to be classifies as skin sensitizer, according to the CLP Regulation (EC) No 1272/2008.